Electric switch



Jan. 3, 1939. R; F. SAMBLESON ELECTRIC SWITCH Filed March 12, 1937 lllInventori 1 dml b m a Lu P e His Attorney.

Patented Jan. 3, 1939- PATENT OFFICE 2,142,155 ELECTRIC swrron Robert F.Sambleson, Bridgeport, Conn, assignor to General Electric Company, acorporation of New York Application March 12, 1937, Serial No. 130,497

9 Claims. '(o1. 20o 152 The present invention relates to electricswitches of the type having liquid contact circuit closers forcontrolling the fiow of current.

The object of my inventionis to provide an improved construction andarrangement in switches of this type.

In the accompanying drawing, Fig. 1 is a front elevation, partly brokenaway, of a switch embodying my invention; Fig. 2 is a sectional endelevation of the switch; and Fig. 3 is an end view of the circuitcloser, partially broken away, to show the construction and operation.

Referring to the drawing, I have illustrated my invention using a liquidcontact circuit closer having a pair of opposed cup-shaped metalterminals I which are separated by an insulating diaphragm 2 ofrefractory material, such as a ceramic. The edges of the terminals aresealed by a glass bead 3 which also seals the junctions between thediaphragm and terminals. Within the space enclosed by the terminals is asuitable quantity of mercury 4 which forms the conducting medium betweenthe terminals. In the .manufacture of circuit closers the space enclosedby the terminals is evacuated and filled with hydrogen at a pressure ofone or more atmospheres. This increases the curernt interruptingcapacity of the circuit closer. As shown in Fig. 3'the diaphragm 2 isprovided with an opening 5 which is submerged in the mercury when thecircuit closer is in the current conducting position. When the circuitcloser is in the current interrupting position, the opening is above themercury as shown in dotted lines in Fig. 3 and the circuit between theterminals is therefore interrupted by the insulating diaphragm. Due tothe construction of the circuit closer, the interruption of the circuitbetween the terminals takes place in the mercury as the circuit closeris turned so that the opening 5 approaches the dotted line position. Theabove described construction is typical of liquid contact circuitclosers which are suitable for use in switches embodying my invention.

The liquid contact circuit closer is carried within a cylindrical metalhousing 6. On the outside of the housing are threaded nuts I which areadapted to secure the housing toa suitable support by clamping thesupport between the nuts. At the lower end of the housing is a disk 8 ofinsulating material which is held against a shoulder 9 by the spun-overportion I 0. The disk is provided with rectangular slots ll throughwhich contact strips l2 loosely extend. In the plane of the disk 8, thecontact strips l2 are provided with notches extending from each edgethereof. The ends M which project below the disk 8 are twisted at anangle to the slots II, the shoulders l5 at the lower side of the notchesthereby preventing upward movement of the 5 contact strips through theslots. Above the disk 8, the contact strips are provided with ears l5 ateach side thereof which are bent at right angles to the slots ll therebypreventing downward movement of the contact strips through the slots. 10The lower edges of the ears l5 are flush with the upper surface of thedisk and prevent downward movement of the contact strips through theslots H The ears l5 on'each of the contact strips l2 project inwardlywithin the ends of the terminals of the circuit closers. In the upperends of the contact strips are spherical projections l6 which fit incomplementary depressions in the terminals of the circuit closers. Theprojections and depressions provide a construction which supports thecircuit closer for rotation with respect to the contact strips and. alsoserves to make the electrical connection between the contact strips andthe terminals. The circuit closer fits within a depression I! on theunderside of a spherical handle IS. The handle is provided with aprojection IS on its upper surface which provides a convenient grip forturning the handle. The circuit closer is non-rotatably connected to thehandle by means of arcuate members 20 of insulating material which fitover the ends of the terminals of the circuit closer and are keyedthereto by means of projections 2| which fit into depressions 22 in theterminals. On the outer periphery of the members 20 are projections 23which fit into complementary depressions in the recess I1 andnon-rotatably secure the circuit closer to the handle. The side walls 24of the depression I! bear against the outer surface of the contactstrips l2 and hold the projection I6 of the contact strips in thedepressions in the circuit closer terminals. When the handle is in placethe circuit closer is therefore securely held between the contactstrips. The upper end of the housing 6 is provided with a spherical seat25 which serves as a bearing for the handle. The seat also prevents theremoval of the handle through the upper end of the housing. The angularmovement of the handle is limited by the engagement of the ends 26 ofthe members 20 with the ears l5.

In the assembly of the switch, the members 20 are mounted on theterminals of the circuit closer and the circuit closer is assembledbetween the contact strips, the projections 16 on the contact 66 stripsfitting in the depressions in the circuit closer terminals. The circuitcloser is then inserted in the depression II in the handle. In thisposition the projections 23 on the members 20 fit in complementarydepressions in the bottom of the recess 11 and the walls and the sidewalls 24 of the recess engage the outer surfaces of the contact stripsI2 and hold the contact strips in engagement with the terminals. Theassembly is then inserted through the lower end of the -housing, thedisk 8 placed over the contacts, and the assembly is secured in placeby. clamping the disk 8 against the shoulder 9 by means of the spun-overportion Ill. The ends ll of the contact strips are then twisted at anangle to the slots I I, thereby securing the contact strips to the disk.The circuit closer is now supported for rotation by the projection I6 onthe contact strips l2.

What I claim as new and desire-to secure by Letters Patent of the UnitedStates is:

1. In an electric switch, a liquid contact circuit closer having opposedterminals, contacts engaging said terminals, said contacts and saidterminals having 'interfltting, portions whereby the circuit closer issupported for rotation with respect tothe contacts, a handle having aportion fitting over said contacts serving to hold thecontacts againstthe said terminals, and means connecting the handle and the circuitcloser whereby the circuit closer is rotated by the handle.

2. In an electric switch, a liquid contact circuit closer having opposedterminals, contact strips engaging said terminals, said contacts andsaid terminals having interi'ltting portions whereby the circuit closeris rotatable with respect to' 'the contacts, a handle having a recessreceiving said circuit closer andghavlng walls holding said contactsagainst said terminals, and means connecting the handle and the circuitcloser whereby the circuit closer is rotated by the handle.

3. In an electric switch, a liquid contact circuit closer having opposedterminals, contact strips engaging said terminals, said contacts andsaid 4:; terminals having interfitting portions whereby the circuitcloser is rotatable with respectto the contacts, a handle having arecess receiving said circuit closer and having walls engaging saidcontacts and holding said contacts against said terminals, and a memberhaving parts non-rotatably engaging said recess and one of saidterminals for connecting the circuit closer and handle whereby thecircuit closer is rotated by the handle.

4. In an electric switch, a liquid contact circuit closer having opposedterminals, contact strips engaging said terminals, said contacts andsaid terminals having interfittlngportions whereby the circuit closer isrotatable with respect to the contacts, a handle having a recessreceiving said circuit closer and having walls engaging said contactsand holding said contacts against said terminals, 9. member having partsnon-rotatably engaging said recess and one of said terminals forconnecting the circuit closer and handle whereby the circuit closer isrotated by the handle, and parts on said member arranged to engage oneof said contacts whereby the angular rotation of the circuit closer islimited.

5. In an electric switch, a liquid contact circuit closer having opposedterminals, contact strips engaging said terminals, said contacts andsaid terminals having interiitting portions whereby the circuit closeris supported for rotation with respect to the contacts, a handle havinga recess receiving said circuit closer and having walls holding saidcontacts against said terminals, means connecting said handle to saidcircuit'closer whereby the circuit closer is rotated by the handle, ahousing having an opening through which the handle projects, said handleand said housing having cooperating bearing surfaces preventing Itheremoval of the handle through said openin and means securing saidcontact strips to saidhouslng whereby the circuit closer is heldtherein;

6. In an electric switch, a liquid contact circuit closer having opposedterminals, contacts engaging said terminals, said contacts and saidterminals having interfltting bearing surfaces of relatively greatdiameter compared to the thickness of the contacts whereby the circuitcloser is sup ported for rotation with respect to the contacts, thebearing surfaces of the contacts comprising projections, a handle havinga portion fitting over the contacts and serving to hold the contactsagainst the terminals, and means connecting the handleand circuit closerwhereby the circuit closer is rotated by the handle.

7. In an electric switch, a liquid contact circuit closer having opposedterminals, contacts fitting over the ends of the terminals, saidcontacts and said terminals having interfitting portions whereby.thecircuit closer is rotatable with respect to the contacts, a handlehaving a portion preventing endwise removal of the contacts off theterminals, and means connecting the handle and circuit closer wherebythe circuit closer is rotated by the handle.

'8. In aneIectric switch, a liquid contact circuit closer having opposedterminals, contact strips engaging said terminals, said contacts andsaid terminals having interfitting bearing surfaces of relatively greatdiameter compared to the thickness of the contacts wherebythe circuitcloser is rotatable with respect to the contacts,

the bearing surfaces of the contacts comprising projections, a handlehaving a recess receiving the circuit closer and the contacts, and meansconnecting the handle and the circuit closer whereby the circuit closeris rotated by the handle.

circuit 55

